The resonator fiber optic gyroscope (RFOG) is a promising contender for next generation navigation gyroscope. It has the potential to provide a navigation grade solution with the combination of low cost, small package size and weight. The RFOG uses at least two laser beams, at least one propagates around a resonator coil in the clockwise (CW) direction and the other in the counter-clockwise (CCW) direction. In the operation of a resonant fiber optic gyroscope (RFOG), it is desirable to lock the frequencies of the laser light sources to the resonance frequencies of the fiber optic ring resonator using high bandwidth electronic servos. Current baseline RFOG designs often use the gyroscope's fiber ring resonator sensing coil as a reference resonator to stabilize a master laser. Then the master laser stability is transferred to slave lasers using high speed optical phase lock loops. This results in reduced phase noise relative to the gyro resonator sensing coil, which improves gyro performance. One disadvantage of this approach is that the master laser must co-propagate with one of the slave laser beams that are used for rotation sensing. The beating between these two beams can cause rotation sensing errors. Optical filters have also been utilized to clean up phase noise on the output of slave lasers. However, a disadvantage to these approaches is that the optical filters often need to be combined with some kind of temperature control to make their operating frequencies track the resonant frequencies of the gyro resonator sensing coil. This temperature control introduces significant power dissipation and cost to the gyro.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for systems and methods for fiber optic gyroscopes utilizing reference ring resonators.